| 摘要 |
PURPOSE: To make it possible to determine an exact feedback quantity for potential control of a photoreceptor. CONSTITUTION: The control input values of an electrostatic charger 2 and an exposing device 3 are slightly changed prior to image formation and the change rates of the surface potential of this time is measured by a potential sensor 8. These change rates are respectively inputted to memories 17, 18. A feedback calculating section 20 reads the change rates of the surface potential out of the memories 17, 18 at the time of actually forming images. The feedback quantity of the electrostatic charger 2 and the feedback quantity of the exposing device 3 are respectively calculated by a prescribed calculation equation using the change rates, the target potential value and the actually measured potential value. The feedback quantity is supplied to an impressed voltage control section 15 and an exposure quantity control section 16. The impressed voltage control section 15 and the exposure quantity control section 16 control the electrostatic charger 2 and the exposing device 3 by using the feedback quantity. |
